Mass effect on Quantum Rotational state of Molecular D2 on MgO(001) surface

Abstract Attention is focused on the rotational motions of a light D2 molecule rotating freely over the MgO (001) surface. Perturbation theory (PT) calculations are also utilized to investigate the rotational motions of D2 at the core of a p-type unit cell. These calculations show that the molecular axis of D2 is azimuthally delocalized, and thus it can pass through a potential energy barrier, whose height exceeds its' rotational energy. Therefore, the simulated structures are actually “c” type instead of “p” type. Additionally, the effect of mass on azimuthal quantum delocalization is examined and persists for H2, HD, D2 and T2 species. Including the quantum rotational effects of those species will convert these ad-layer topology into c-type structures. Our results match the neutron scattering and helium atom scattering results at low temperatures.